1. Field of the Invention
The present invention relates to a femoral broaching apparatus for use in preparing a femoral cavity for implantation of a prosthetic joint in the case of a surgical artificial hip-joint replacement arthroplasty, and more particularly, to a femoral broaching apparatus which can prepare a femoral cavity having accurate shape and position using vibration under operation of a fixing guide unit.
2. Background of the Related Art
Artificial hip joint replacement arthroplasty involves the fixation of a prosthetic hip joint to a proximal end of the femur. For this, the damaged femoral head is first removed, and then the prosthetic hip joint is inserted into the femur so as to come into smooth contact with the pelvis without pain. Here, the prosthetic hip joint serves as a joint prosthesis for connecting the femur to the pelvis. For the secure and durable fixation of the femoral prosthesis, its design has been evolved during past decades. Currently, except very unusual case, the femoral prosthesis is designed to fill the proximal femur. Proximal femoral spongeous bone is shaped as the prosthesis during the surgery by drill or broach. Then the prosthesis inserted into the femoral cavity which prepared. Machined cavity should be aligned and connected with the original femoral cavity. Otherwise the femoral prosthesis fails to obtain proper fixation.
After the completion of implantation, the joint prosthesis is securely fixed relative to the femur and is adapted to transmit the weight of a patient to the femur. Examples of methods for fixing the joint prosthesis to the femur include an adhesive method using a bone cement, and a non-adhesive method using ingrowth of new tissue of the femur into the joint prosthesis for achieving mechanical interlocking therebetween. Although one of the fixing methods can be appropriately selected and used according to the patient's condition, specifically, in the case of the non-adhesive method, it is known that the shape accuracy of the femoral cavity largely affects the results of the surgical operation.
In addition to the shape accuracy thereof, the positional accuracy of the femoral cavity is also important. If the femoral cavity is not at an intended accurate position, it may result in distortion or shortening of the patient's leg after the completion of the prosthetic hip replacement.
In the prior art, for the preparing of the femoral cavity, a surgical broach is manually inserted into the femur through hammering. Here, the surgical broach has the same shape as that of the prosthetic joint to be implanted in the femur. This method, however, has a problem of inaccuracy in shape and position of the resulting femoral cavity. Instead of such a manual hammering method, further, a high-speed pneumatic vibrator is used to insert the broach into the femur. This has been proved to enhance operational convenience as compared to the manual hammering operation, but it still suffers from poor reliability in the accuracy of shape and position of the resulting femoral cavity.
As yet another method, a computerized robotic milling system is used for the preparing of the femoral cavity. In the case of this robotic system, although it can successfully prepare the femoral cavity having desired accurate shape and position, it has the problems of its costly price and relatively long operational time. In some cases, furthermore, there exists the necessity of additional surgical procedures, resulting in enormous cost load as well as the risk of thrombosis due to excessive bleeding of the patient.